Frank Martin (1890 - 1974), next to Arthur Honegger and Willy Burkhard, is one of the most famous Swiss composers of the 20th century. His works have a unique musical language that combines elements of French Impressionism with new music. Started in 1922 and completed in 1926 the Mass for Double Choir was not released by Martin for publication and performance until 1963. As a 12 year old he heard a performance of J S Bach "St Matthew Passion" which affected him profoundly and may have contributed to his decision to keep the "Mass" locked away for almost 40 years. Beside the genius of Bach, Martin felt his own composition to be inadequate. It is an intensely personal work and is considered to be one of the finest a cappella works of the 20th century.